python sort list of tuples in list by value

Question

I have the following List with a List of tuples:

[[('Armin', 1.0), ('Doris', 0.2240092377397959)], [('Benjamin', 1.0), ('Doris', 0.3090169943749474)], [('Caroline', 1.0), ('Benjamin', 0.2612038749637414)], [('Doris', 1.0), ('Benjamin', 0.3090169943749474)], [('Ernst', 1.0), ('Benjamin', 0.28989794855663564)]]

This is a list of tuples in a list. I would like to sort it by the value of the second tuple in each list. For instance - I would like to have this result of my orderedList:

[[('Benjamin', 1.0), ('Doris', 0.3090169943749474)],[('Doris', 1.0), ('Benjamin', 0.3090169943749474)],[('Ernst', 1.0), ('Benjamin', 0.28989794855663564)],[('Caroline', 1.0), ('Benjamin', 0.2612038749637414)],[('Armin', 1.0), ('Doris', 0.2240092377397959)]]

I was not able to manage it with sorted and lambda.

Could you please tell me how to do it?

It is not quite that same as that. He also want the top level list sorted by the sub-sub elements that are not equal to 1.0 — James, Nov 12 '17 at 17:00

score 1 · Accepted Answer · answered Nov 12 '17 at 16:59

This should do it:

l = [[('Armin', 1.0), ('Doris', 0.2240092377397959)], [('Benjamin', 1.0), ('Doris', 0.3090169943749474)], [('Caroline', 1.0), ('Benjamin', 0.2612038749637414)], [('Doris', 1.0), ('Benjamin', 0.3090169943749474)], [('Ernst', 1.0), ('Benjamin', 0.28989794855663564)]]

sorted(l, key=lambda x: x[1][1], reverse=True)

Explanation: Passing the key parameter in sorted allows you to sort an object by a key that you specify. In this case, the key we wan to sort on is the second value in the second item of the list. Passing the reverse=True parameter sorts the list in descending order.

score 0 · Answer 2 · answered Nov 12 '17 at 17:01

I think you want this. Sort each sub list by the second value, then sort the top level list by the number of the second value in the sublists.

sorted([sorted(e, key=lambda x: x[-1], reverse=True) for e in x], 
       key=lambda x: x[-1][-1], reverse=True)

# returns:
[[('Benjamin', 1.0), ('Doris', 0.3090169943749474)],
 [('Doris', 1.0), ('Benjamin', 0.3090169943749474)],
 [('Ernst', 1.0), ('Benjamin', 0.28989794855663564)],
 [('Caroline', 1.0), ('Benjamin', 0.2612038749637414)],
 [('Armin', 1.0), ('Doris', 0.2240092377397959)]]

score 0 · Answer 3 · answered Nov 12 '17 at 17:06

You can try this:

s= [[('Armin', 1.0), ('Doris', 0.2240092377397959)], [('Benjamin', 1.0), ('Doris', 0.3090169943749474)], [('Caroline', 1.0), ('Benjamin', 0.2612038749637414)], [('Doris', 1.0), ('Benjamin', 0.3090169943749474)], [('Ernst', 1.0), ('Benjamin', 0.28989794855663564)]]
final_s = [[(a, b) for a, b in zip([c for c, d in i], [d for c, d in i][::-1])][::-1] for i in sorted(s, key=lambda x:x[-1][-1])[::-1]]

Output:

[[('Benjamin', 1.0), ('Doris', 0.3090169943749474)], [('Doris', 1.0), ('Benjamin', 0.3090169943749474)], [('Benjamin', 1.0), ('Ernst', 0.28989794855663564)], [('Benjamin', 1.0), ('Caroline', 0.2612038749637414)], [('Doris', 1.0), ('Armin', 0.2240092377397959)]]

python sort list of tuples in list by value

3 Answers3